Process of treating steam-boilers for preventing fractures and explosions



(N0 Model.)

C. S. BBAUGH. PROCESS oF TREATING STEAM BOILERS PoR PREVENTING'FRAGTURBSAND BXPLOSIUNS.

No. 329,446. Patented Nov. 3, 1885.

N, PETERS, Phnwuihognpher. washingmn. D. C.

' UNITED STATES PATENT OFFICE.

CHARLES S. EBAUGH, OF ST. LOUIS, ASSIGNOR OF ONE-TENTH TO CHARLES D.MOODY, OF WEBSTER GROVES, MISSOURI.

PROCESS 0F TREATING STEAM-BOILERS FOR PREVENTING FRACTURES ANDEXPLOSIONS.

SPECIFICATION forming part of Letters Patent No. 329,446, dated November3, 1885.

Application filed September 8, 1885. Serial No. 176,477. (No specimens.)

To all whom it may concern:

Beit known that I, CHARLES S. EBAUGH, of St. Louis, Missouri, have madea new and useful Improvement in Processes of Treating Steam-Boilers forPreventing Fractures and Explosions, of which the following is a full,clear, and exact description.

The improvement is based upon the fact, ascertained by me afterprolongedinvestigation, that the plates of steamboilers, if notoriginally so, in use become, from various causes, crystallized,andtherefore weakened and more liable to break, and that with the maximumauthorized working pressure cracks occur only in plates whose metal iscrystallized, and upon the further fact that by annealing crystallizediron or steel is reconverted into uniformly-tough ductile metal.

The improvement consistsin takinga steamboiler just as it is after itsplates have from use or other cause become crystallized, and without inany manner changing its constitution, and preferably in situ, andwithout any water in it, subjecting it to an annealing-heat, and afterthoroughly so heating allowing it to cool gradually, whereupon it willbe found restored to its original condition and strength, and if theplates of the boiler when originally made were crystallized the boilerwill be materially bettered by the treatment.

The most desirable mode of carrying out the improvement is illustratedin the annexed drawings, making part of this specification, in

which- Figure 1 is a vertical longitudinal section of an ordinarysteam-boiler of the cylinder type having two tlues and set in theordinary manner. The section is on the line 1 l of Fig. 2. Fig. 2 is avertical crosssection on the line 2 2 of Fig. 1.

The same letters of reference denote the same parts.

The water being drawn out of the boiler A, a wood-fire, B, (as fuelcontaining sulphur should not be used,) is placed in the fire-place Cand the boiler subjected to heat proceeding from the fire, just as whenthe boiler is filled with water and used as a steam-generator. Thefiring is continued until the entire boiler is subjected to anannealing-heat, and 5o until it assumes the proper annealing color,following in this respect the most approved practice in annealing ironor steel, and according to the character of the metal of which theboiler is composed. (I have ascertained that if the plates are heatedeven to a white heat no injurious result ensues.) The tire is thenwithdrawn and the boiler allowed to gradually cool, as in annealing. Itwill then be seen that the seams and rivets are in no 6o wise impaired,and that the metal in the plates is no longer crystallized,but tough andstrong.

The customary inclosing-walls,D D, and covering E, constitute a suitablefurnace or box, not only for enabling the heat to be applied to theboiler, but also for enabling it to be cooled gradually.

In presenting this application I beg to state that it is based upon along series of tests with actual steam-boilers, both single ones and inbatteries. At least one hundred boilers have been subjected, under mypersonal su perinlendence, to the above-described treatment. It wasproblematical whether the desired heat could be applied to a boiler as aunit without injuring its form or weakening it at the joints. It alsoinvolved a long period of time for a comparison to be instituted betweenboilers not thus treated and boilers which had been subjected to thetreatment, and a reliable conclusion to be reached; but after theserepeated and prolonged tests, madeat first, and almost always afterward,at my own cost, risk, and responsibility, I am prepared to state thatthe treatment in question positively prevents fractures in boilerplates,and with any working pressure equal to the test applied by theGovernment explosions will not occur. 9o

The improvement is adaptable to any of the ordinary forms ofsteam-boilers, and to locomotives as well as to stationary boilers.

I have further demonstrated that fractures occur in boiler-platesbecause of isolated strains due in turn to unequal, contraction andexpansion7 but only in plates Whose metal, is crystallized.

I claim- The herein described mode of treating 5 steam-boilers, forpreventing fractures and explosions, with a working steam-pressure,which Consists in subjecting the entire boiler,

Without any Water in it, to an annealing heat, and allowing it' to coolgradually, substantially as described.

CHARLES S. EBAUGH. Witnesses: l C. D. MooDY, y v J. W. HOKE.

